RCA RecordsAfter releasing a teaser a while back, Avril Lavigne's new single "Here's to Never Growing Up" is now officially available for download on iTunes. Also available: a lyric video that features content submitted by Avril fans.

Avril asked her fans to send in photos or video of themselves illustrating the theme of "Here's to Never Growing Up," and the lyric video incorporates all those images. Fans are seeing wearing silly costumes, goofing around, doing childish things like holding teddy bears and building snowmen, and generally having a ball.

The super-catchy song, somewhat reminiscent of Avril's signature tune "Complicated," features a chorus that goes, "Singing Radiohead at the top of our lungs/With the boom box blaring as we're falling in love/Got a bottle of whatever, let's get in this truck/Singing 'Here's to never growing up'/We'll be running down the street yelling 'kiss my a**'/I'm like, 'Yeah, whatever,' we're still living like that/When the sun's going down, we'll be raising our cups/Singing 'Here's to never growing up'."

Avril will appear on Chelsea Lately April 11 to discuss the song, which she co-wrote with her fiance, Nickelback'sChad Kroeger. She'll perform it for the first time on TV April 26 on The Tonight Show with Jay Leno.